This investigation deals with the ocular responses to adrenergic agonists and with the role of adrenergic mechanisms in the regulation of intraocular pressure and intraocular vascular circulation. Ongoing studies include: 1) Elucidation of the biphasic pressure and outflow resistance response to alpha and beta adrenergic agonists; 2) Correlation of the tissue distribution of adrenergic agonists applied topically to the time course of the ocular response; 3) The development of a new methodology for the measurement of opthalmic arterial pressure and its application to study of vascular responses to adrenergic agonists and the central neural agonist, clonidine. BIBLIOGRAPHIC REFERENCES: Krieglstein, G.K. and Langham, M.E. (l975). The influence of body position on the intraocular pressure of normal and glaucomatous eyes. Ophthalmologica 171: 132. Quigley, H.A. and Langham, M.E. (l975). Comparative intraocular pressure measurements with the pneumatonograph and Goldman tonometers. Amer. J. Ophthal. Chicago 80:266.